ip tuntap: Added missing commands in usage

show, list, lst and help commands were not printed in usage.
Signed-off-by: Vadim Kochan <vadim4j@gmail.com>

ip/iptuntap.c

@@ -36,7 +36,7 @@ static void usage(void) __attribute__((noreturn));
 
 static void usage(void)
 {
-	fprintf(stderr, "Usage: ip tuntap { add | del } [ dev PHYS_DEV ] \n");
+	fprintf(stderr, "Usage: ip tuntap { add | del | show | list | lst | help } [ dev PHYS_DEV ] \n");
 	fprintf(stderr, "          [ mode { tun | tap } ] [ user USER ] [ group GROUP ]\n");
 	fprintf(stderr, "          [ one_queue ] [ pi ] [ vnet_hdr ] [ multi_queue ]\n");
 	fprintf(stderr, "\n");